Fire and temperature alarm or indicator.



G. SMITH. FIRE AND TEMPERATURE ALARM 0R INDIGATQR.

APPLICATION FILED MAY 22, 1908.

Patented Dec. 1,1908.

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Patented Dec. 1, .908.

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UNITED STATES PATENT OFFICE.

GEORGE LAWRENGESMITH, OF ABERDEEN, SCOTLAND.

FIRE AND TEMPERATURE ALARM OR INDICATOR.

Specification of Letters Patent.

Patented Dec. 1, 1908.

' Application flled'lay 22; 1908. Serial No. 434,391.

'States Patent No. 850681 dated 16th April 1907 I have described a fireand temperature alarmor indicator apparatus operated by pneumaticexpansion, and in which a metal tube of small diameter is employedcontainmg air at atmospheric pressure, having an air vent or escape fromthe tube to the atmosphere, while the tube communicates with a closedexpansible case. Thus upon a gradual or ordinary rise of temperatureoccurring in a place through which the tube passes, the expanded air inthe tube will pass slowly through the air vent without giving any'alarmindication, while, on the other hand, when the air in the tube issuddenly heated, by a fire for instance, the ,expansible case will beimmediately expanded and an electric circuit will be, by that movement,closed or broken for the purpose of sounding any convenient alarm. In alater United States application by myself filed on the 19th March 1908Ser1al No. 422147 (Patent 'No. 891743 dated 23d June 1908) I arrangedthe expansible case, as well as the air vent which communicates with thetube, Within the interior of a closed air chamber containing air atgreater than atmospheric pressure, the said air pressure communicatingwith the tube through the adjustable vent, so that the air tube, passingaround the room or other place, contained still air under greater vthanatmospheric pressure, and the object I had in v1ew-and which object wasattained bythat inventione-was the provision of a separate andindependent signal which would be given in the event of the smalldiameter metal tube becoming fractured or broken. With this arrangement,upon the pressure air in the tube being suddenly expanded as bya'fi're,the expansible case within the air pressure chamber expanded,and completed an electric circuit-by the act of its expansion to operatea fire alarm, whereas if a break occurred in the tube, the pressure airwould pass away through such a break from the expansible case, and thecollapse of the said case would ,come exhausted and require pumpincomplete another electric circuit and sound What I termed atrouble-call.

Now according to the present invention, I

connect the tube to a reservoir containing pressure air or gas, which isadmitted to the tube from that reservoir through some regulated passage,while the pressure air is allowed to escape from the other end of thetube to the atmosphere also by a regulated passage, so that a normalpressure is maintained in the length of tube while there is also aconstant flow of air taking place throughout the air circuit. The tubethrough which this air flow takes placeand which I will term theindicating tube-passesaround the room or building to be protected,

and communicates, as before, with the interior of an expansible case,and as in the last stated arrangement, thisexpansible case is located inan air-tight pressure chamber with which an adjustable air vent from thetube also communicates. There is a passage from the air pressure chamberto the interior of a second expansible case, which, in the presentinvention, is to give the trouble-call when there is either a stoppageor a break in the indicating tube or any other part of the air circuit:With this arrangement, should there be a stoppage in the air circuit,say by'the indicating tube becoming crushed, the pressure of air in thesaid indicating tube, and consequently in the air pressure chamber, willaccumulate by reason of its still passing into the said'tube through theregulated passage, and therefore the expansible case-which 1 term thetrouble-call casewill become expanded and complete an electric circuitand sound a trouble-call to indicate that the apparatus is out of order.On the other hand, should a break occur in the tube or in some other artof the air circuit, the air pressure wil be immediately reduced, and thetrouble-call case will contract and again give a trouble-call. Likewise,should the air pressure reservoir beu 7 the pressure will fall in thetube and a so iii the expansible case which gives the troublecall, thelatter case willvcontract, and again a trouble-call will be given. Inother respects, the apparatus will act in the manner of the apparatus Ihave previously referred to, that 1s, should a fire occur, the air inthe indicating tube will be suddenly expanded, will not have time topass through the air vent into the pressure chamber, but will ex pandith'e fire-indicating expansible case and into the tube from thepressure reservoir by means of an adjustable passage, but instead I mayemploy any ordinary construction of pressure reducing valve, and I maycarry the opposite end of the indicating tube into an air-tight chambercontaining the troublecall expansible case, provide an ordinaryadjustable air vent from the latter air-tight chamber to the atmosphere,and then the operation of the apparatus will be precisely the same aspreviously described, there being a constant flow of pressure airthrough the air circuit.

By this invention, therefore, not only is a fire indicated by theexpansion of the firealarm expansible case, caused by the indicatingtube being subjected to sudden heat and the air therein suddenlyexpanded, but also a trouble-call is given, either when a break oraccidental escape occurs in the air circuit, or when the air circuitbecomes accidentally stopped or blocked by for instance the crushing ofthe indicating tube.

The invention will be described with reference to the examples ofconstruction shown on the accompanying drawings, whereon Figure 1 showsa diagrammatic sectional elevation of a complete apparatus, and Fig. 2 afront sectional elevation on the line X Y of Fig. 1 looking in thedirection of the arrow, and showing the interior of the air.

pressure chamber and the fire-indicating expansible case, but drawn'to asmaller scale than Fig. 1. Fig. 3 is a view similar to Fig. 1 butillustrates a modified arrangement.)

Referring to Figs. 1 and 2, I provide a reservoir 1 to contain air atpressure, which air can be pumped in by any suitable handpump, or asshown on the drawings, I may provide a primary reservoir 2 containingair or gas at any desired pressure, from which the reservoir 1 can besupplied, by means for instance of a pressure reducing valve 3 of anyknown or convenient construction; the reservoir 1 is fitted with anordinary pressure gage 4.

From the reservoir 1, in the example now described, the airpassesby-means of an adjustable vent or regulated passage 5 controlledfor instance by an ordinary screwdown valve Gto the indicating tube 7which is to extend around the building or place to beprotected withinwhich a fire is to be indicated, and at the opposite end of the tube isan adjustable air vent 8, which is so regulated, that there normallyexists an air pressure in the tube 7 between the air, vent 5 and the a rvent 8, while at the same time there is a constant flow of air takingplace through the said tube 7.

The tube 7, by an extension 9, extends and communicates with a passage10 in a metal casing 11, and communicates with the interior of anexpansible case 12, which is located in an air-tight chamber 13 of thecasing 11, while also communicating with the chamber 13 is an adjustableair vent 14 from the passage 10 to the chamber 13; the air vent 14 mayconsist, of a comparatively loosely fitting screw having a porous andcompressible washer beneath its-head.

The expansible case 12 carries a contact 15, so that when the air issuddenly expanded in the air circuitby the action of fire upon the tube7the expanded air will expand the case 12 before the air has time topass by the air vent 14, and the case 12, so expanding, will bring thecontact 15 into contact with a metal spring 16 insulated from the casing11, and so close a fire-alarm electric circuit and sound a bell or othersignal 17.

The chamber 13 communicates, by a passage 18, with an expansible case 19carrying electric contacts 20 and 21, between which is located a spring22 of conducting metal carried by but insulated from the metal casing 11and electrically connected to a troublecall bell or other alarm device23. The expansible trouble-call case 19 is located in a compartment 24,which isopen to the atmospheric air. Vith this arrangement, should astoppage or block occur in the tube 7 for instance so that air-cannotpass, the pressure will gradually accumulate or increase in the passage10, and will also, by the air vent 14, increase in the air-tight chamber13, and the trouble-call case will be expanded, bring the contact 20into contact with the spring 22, and sound the trouble-call 23,indicating that the apparatus should have attention.

Should a break occur and the air escape from the tube 7 the pressurewill decrease in the passage 10, and in the air-tight chamber 13, andalso in the trouble-call case 19, and cause the contact 21 to contactwith the spring 22 and again sound a trouble-call.

If so desired, the exhaustion of the reservoir 1 may be indicated 'bythe pressure gage 4 having electric connections which sound an alarmupon the pressure a sufficiently low pressure.

The arrangement shown at Fig. 3 differs from the arrangement shown atFigs. 1 and 2, in that a pressure reducing valve 25 of any ordinary orwell known construction is employed, through which air from thereservoir l is admitted to the tube 7 while the opposite end of the tube7 is caused to enter the compartment 24 of the metal casing 11, whichcompartment 24, in this instance, is air-tight, and instead of theadjustable air vent 8 being located at the end of the tube 7 a similaradjustable air vent 26 is provided from the compartment 24. In 'otherrespects the apparatus is similar, audit will be understood that thefire alarm is given in pregage indicating cisely the same way, whileshould the tube 7 become stopped or blocked, the air pres-' sure in thecompartment 24 would gradually pass away by the air vent 26, and the airpressure in the interior of the trouble-call case 19 and in the chamber13 would not escape, and consequently, owing to the difference ofpressures between the interior and exterior of the trouble-call case 19the latter would expand and complete the trouble circuit; should a breakor escape occur, in for instance the tube 7, the pressure would quicklypass away from the compartment 24 through the break in the tube, whilethe pressure within the chamber 13 and troublecall case l9wvould not soquickly pass away, because its only passage would be by the adjustablevent 14, and therefore until the pressure in the interior and upon theexterior of the case 19 became equalized, the contact 20 would be heldin contact with the spring 22 and a trouble-call would be given.

.It will be understood by neference'to the examples which have beendescribed, that anygradual rise or fall of temperature will not operatethe fire-alarm case 12, as there is time "for any slow variation ofpressure in the tube 7 to balance equally outside as well as inside saidcase through the adjustable air vent 14;, so that by adjusting this airvent any desired compensation can be obtained; neither will slow changesof temperature affectthe trouble-call case 19.

What I claim as my invention and desire to secure by patent is 1. Infire and temperature alarms; the combination with a metal tube extendingthrough a place where a sudden rise of temperature is to be indicated, astorage reservoir to contain pressure air, means for admitting aregulated supply of air from said reservoir into one end of said tubeand means for permitting a regulated escape of pressure air from theother end of said tube to maintain a constant flow of pressure airtherethrough; of an air-tight ressure chamber, a closed expansible caseocated in said chamber with the interior of which expansible case saitube communicates, an air vent for permitting air to pass slowly betweensard tube and said chamber, and means by which a'signal is automaticallygiven upon a stoppage of the flow of pressuge air, or upon a breakoccurring, in said tu e.

2. In fire and temperature alarms; the combination with a metal tubeextending through a place where a sudden rise of temperature is to beindicated, 'a storage reservoir to contain pressure air, means foradmitting a regulated supply of air from said reservoir into one end ofsaid tube and means for permitting a regulated escape of pressure a1rfrom the other end of said tube to maintain a constant flow of pressureair therethrough; of an air-tight pressure chamber, a closed expansiblecase located in said chamber with the interior of which case said tubecommunicates to actuate said case by sudden expansion of air, anelectric fire alarm, means for completing an electric C11- cuit by themovement of said case to actuate said alarm,,said tube having a vent forperand said chamber, means for adjusting said vent, a second closedexpansible case located on the exterior 0% said chamber with theinterior of which case said chatnber communicates to give movement tosaid case upona stoppage of flow of pressure air in said tube or upon abreak occurring in said tube, an electrically operated trouble alarm,

cuit by movement of said second expansible case to actuate saidtrouble-alarm.

3. In fire and temperature alarms; the combination with a metal tube, aprimary ary pressure reservoir, a pressure reducing valve, a pipeconnecting said reducing valve With the primary reservoir to supply airthereto, and a pipe from said reducing valve to the secondary reservoirby which the latter is supplied, said metal tube communicating with saidsecondary reservoir, means for regulating the passage of pressure airfrom said secondary reservoir to said tube, an air vent at the oppositeend of said tube and means for regulating the escape of air from saidvent to maintain a constant flow of pressure air through said tube, anair-tight pressure chamber, a closed expansible case located therein, abranch tube extending from said metal tube and communicating with theinterior of said expansible case, an electric fire alarm, and means forcompleting. an electric circuit by the movement of said expansible caseto actuate said fire alarm, said branch tube having an air ventcommunicating with said air-tight pressure chamber, and means forcontrolling the passage of air through said vent between saidgtube andsaid chamber; of a second closed expansible case located on the exteriorof said chamber, a passage-way through the wall of said chambercommunicating with the interior of said second expansible case, an(electrically operated trouble alarm, means said alarm upon theexpansion of said second expanslble case due to stoppage of escompletingan electric circuit to operate said trouble alarm upon the contractionof said second expansible case owin to escape of air from said tube dueto breakage, substantially as set forth.

4. In fire and temperature alarms; the combination with a metal tubeextending I through a place where a sudden rise of temand means forcompleting an electric cir-' reservoir to contain pressure a1r, asecondcape of air from said tube, and means for.

mittin'g air to pass slowly between said tube for completing an electriccircuit to operate t of pneumatic pressure in said tube, a second voirto contain pressure air with which one end of said tube communicates,means for regulating the passage of pressure air from said reservoir tosaid-tube and means for regulating the escape of air from the other endof said tube to maintain a constant flow of pressure air therethrough;of a casing containing an air-tight chamber, a closed expansible caselocated in said chamber with the interior of which expansible case saidtube communicates, said tube having a vent for permitting air to .passslowly between said tube and said chamber, and means for regulating saidvent, an electric fire alarm, means for completing an electric circuitby the movement of said case to actuate said tire alarm upon sudden andunusual increase closed expansible' case located on the exterior of saidcasing, said casing having a passageway communicating between saidair-tight pressure chamber and said second eXpansible case to cause saidsecond expansible case to contract upon accidental escape of air fromsaid tube and consequent reduction of pressure in said chamber, and tocause said second expansible case to expand upon increase of pressure insaid tubeand chamber due to stoppage of said tube, electrical contactsoperated by the movements of said second expansible case, and anelectric trouble-call alarm device operated by said movements of saidsecond expansible case, substantially as set forth.

5. In fire and temperature alarms; the (-ombinati0n with a metal tube, astorage resl perature is to be indicated, a storage reser- J ervoirtocontain pressure air, a pressure reducing valve communicating withsaid reservoir, oneend of said 'metal tube communicating with saidreducing valve to supply said tube with air at regulated pressure, theopposite end of said tube having an airescape vent, means for regulatingthe escape of air through said vent to maintain a constant flow ofpressure air therethrough; of an air-tight pressure chamber, a closedexpansible case located in said chamber with the irr- I terior of whichexpansible case said tube communicates, to expand said case by suddenexpansion of air, an electric fire alarm, means for completing anelectric circuit by the movement of said case to actuate said alarm,said metal tube having an air vent for permitting air to pass slowlybetween said tube and said chamber, means for adjusting said vent, asecond closed'expansible case located on the exterior of said chamberwith the interior of which latter case said chamber communicates to givemovement to said case upon a stoppage of flow of pressure in said tubeor upon a break occurring in said tube, an electrically operated troublealarm, and means for completin an electric circuit by the movement ofsai second expansible case to actuate said trouble-alarm, substantiallyas set forth.

In witness whereof I have hereunto set my hand in the presence of twowitnesses.

GEORGE LAWRENCE SMITH.

Witnesses: I

LEONARD THOMAS, HERBERT D. WISE.

